Mineralogical, Geochemical and industrial use ofbentonites from Ferdows, Kashmar and Ghonabadin comparison with imported activated bentonites

Bentonites from Kashmar, Gonabad and Ferdows were studied and compared with imported types. Bentonites have a very wide range of industrial uses. Chemical and mineralogica l composit ion of montmo rillo nite wit hin t he bentonite control its kind of application. Bentonites from Kashmar have the higbest content of Cao and A120) and K20. High expandibiity, good adhesive property a nd having high content of Na20 indicate that Ferdows bentonites are Na-type. Gonabad bentonites are Na-Ca-Type. Kashmar, Ferdows and Gonabad bentonites were treated for acti vat io n. In term of exc hangable ca t io ns, Kashmar bent o nite is compa rable with imported activated be ntonites from China a nd Turkey . Detemination of Ca and Na montmorionite based on the X-Ray pattern is not very e asy. The position of the first peak of montmorillonite we re compared with Na20 content of bentonites. JJ the first peak of montmorillonite is more than 7.3 degree and t he Na20 co nte nt of bentonite is more than 2 percent, therefore montmorillonite is Na-type. If the first peak is less than 7 degree and Na20 content of bentonite is less than 1.5 percent, the montmorillonite is Ca-type.